1. Field of the Invention
This invention relates to the field of solid state power conversion and more paraticularly to the field of circuits designed for use within switch mode power converters having output voltage levels that are electrically isolated from the input main power bus.
The invention isolated controller circuit is useful for sensing an output voltage level from a power supply measured with respect to an isolated voltage reference such as an isolated ground, comparing the output voltage signal with a precision reference, compensating the output signal with a compensation network selected to enhance the stability of the power converter, and coupling the control signal to an output terminal referenced to a non-isolated voltage reference such as the power return for the input power main. The output control signal referenced to the non-isolated voltage reference system is used to control the duty cycle ratio of the duty cycle converter or pulse width modulated converter.
2. Description of the Prior Art
Presently known isolated controller circuits use opto-electronic coupling for coupling a control signal from a source referenced to an isolated voltage reference to an output terminal referenced to a non-isolated voltage reference. Opto-electronic couplers have undesirable aging properties, are temperature sensitive and are sensitive to radiation effects, such as gamma ray radiation.